1. Field of the Invention
The present invention relates to a light-shielded photosensitive material roll which, in a lighted room, is loaded into a plate making machine using a photosensitive material.
2. Description of the Related Art
An elongated photosensitive material sheet is, in a state of being wound-up in a roll form on a winding core, loaded into a plate making machine which uses a photosensitive material. Usually, the side surfaces of the photosensitive material roll are covered by ring-shaped light-shielding sheets and the periphery of the photosensitive material roll is covered by a light-shielding leader so that the photosensitive material roll can be loaded into the plate making machine in a lighted room. (Hereinafter, a photosensitive material roll which is covered by light-shielding members is called a light-shielded photosensitive material roll.)
A light-shielded photosensitive material roll is usually supported within a plate making machine by a driving shaft which is inserted into the winding core. The diameter of the driving shaft differs in accordance with the type of the plate making machine. Thus, a method is employed in which light-shielding flanged adapters, which have inner diameters which correspond to the driving shafts of various types of plate making machines, are installed at the winding core of the light-shielded photosensitive material roll. The development of adapters for light-shielded photosensitive material rolls has advanced.
Japanese Patent Application Laid-Open (JP-A) No. 2000-181018 proposes an adapter in which a rolling body (an O-ring), which is an elastic body, is disposed at the outer side surface of the tube portion of the adapter which is inserted into the winding core. In accordance with the structure disclosed in JP-A No. 2000-181018, this adapter which is equipped with the rolling body can be securely fixed to the winding core of the light-shielded photosensitive material roll. Further, attachment and removal of the adapter to and from the light-shielded photosensitive material roll is easy.
Moreover, the applicant of the present application has found that, by providing a convex portion, which extends along the lengthwise direction of the tube portion of the adapter, at the outer side surface of the tube portion of the adapter, and by engaging this convex portion of the adapter with a groove which is provided in the winding core of the light-shielded photosensitive material roll and extends along the lengthwise direction thereof, the adapter can be securely installed in the winding core of the light-shielded photosensitive material roll. The present applicant has filed a patent application for an invention based on this finding (see JP-A No. 2001-318451).
It is desirable that the light-shielded photosensitive material roll is a structure that enables a photosensitive material sheet, which has been unwound once, to be smoothly wound up again onto the winding core. However, research conducted by the present inventors has shown that, in a light-shielded photosensitive material roll equipped with adapters, a ring-shaped light-shielding sheet easily slants toward the photosensitive material roll (toward the side opposite the adapter flange) at the time when the photosensitive material sheet is being unwound. When the photosensitive material sheet, which has been unwound from the photosensitive material roll, is wound up again onto the winding core of the original photosensitive material roll, the side end portion of the photosensitive material may contact the surface of the peripheral end portion of the ring-shaped light-shielding sheet, which may cause offset in the winding of the photosensitive material sheet. When such winding offset of the photosensitive material sheet occurs within a plate making machine, the photosensitive material roll must be removed from the plate making machine, and the photosensitive material sheet is exposed and cannot be used. In addition, winding offset is a cause of malfunctioning of the plate making machine.
An object of the present invention is to overcome the above-described problems.
In order to achieve this object, in accordance with an aspect of the present invention, there is provided a photosensitive material roll which can be mounted in a predetermined machine, comprising: (a) a hollow, cylindrical winding core; (b) an elongated photosensitive material sheet wound-up on the winding core; (c) an annular member including a cylindrical portion inserted in an opening of the winding core, and a flange portion extending in a radial direction from one end of the cylindrical portion; (d) a ring-shaped light-shielding sheet disposed between the flange portion of the annular member and the winding core; and (e) an adapter including an adapter tube portion inserted into the cylindrical portion of the annular member, and an adapter flange portion extending in a radial direction from one end of the adapter tube portion, wherein the ring-shaped light-shielding sheet is partially adhered to the adapter flange portion.
In accordance with another aspect of the present invention, there is provided a photosensitive material roll which can be mounted in a predetermined machine, comprising: (a) a hollow, cylindrical winding core; (b) an elongated photosensitive material sheet wound-up on the winding core; (c) a ring-shaped light-shielding sheet including a cylindrical portion inserted in an opening of the winding core, and a ring-shaped sheet portion extending in a radial direction from one end of the cylindrical portion; and (d) an adapter including an adapter tube portion inserted into the cylindrical portion of the ring-shaped light-shielding sheet, and an adapter flange portion extending in a radial direction from one end of the adapter tube portion, wherein the adapter flange portion includes a ring-shaped recess which can receive an outer peripheral portion of the ring-shaped sheet portion of the ring-shaped light-shielding sheet, the recess being formed at a position of the adapter flange portion which position corresponds to the outer peripheral portion of the ring-shaped sheet portion.